Man's 'disturbing' acts on Sydney trains

Police are asking for public assistance in identifying a man believed to have information about a spate of indecent assaults on Sydney trains.

Officers are investigating four separate incidents that occurred between November 2018 and June 2019.

On November 12, 2018 a man sat next to a female passenger on a train from Redfern to Parramatta just after 4pm.

He allegedly started performing a sexual act on himself, causing the woman to scream and move seats.

The man left the carriage shortly after.

On November 19, 2018 at about 10am a woman boarded citybound train on the Blue Mountains line.

When the train arrived at Strathfield a man entered the carriage and asked to sit next to her.

He then allegedly started performing a sexual act on himself.

The woman got off at Central Station, with the man also disembarking a short time later.

On November 30, 2018 just about 4.40pm a man got on a train at Central Station and sat next to a woman before allegedly performing a sexual act on himself.

He then got off at Strathfield station.

On June 3, 2019 around 9pm a man got on the train at Wynyard and asked a woman if he could sit next to her, despite there being numerous other seats available.

A short time later he allegedly started performing a sexual act on himself.

The woman asked him to stop and move away, which he did.

She then approached the guards department and contacted police, with the man disembarking at North Sydney Station.

Police would like to speak to a man who may be able to assist with their inquiries.

He is described as having a tanned complexion, aged between 20 to 30-years-old, of a thin build, approximately 165cm tall with short black hair. He has a sleeve tattoo on his right arm and another tattoo on his left forearm.